FORT COLLINS, Colo. (CBS4) – A family in Fort Collins has filed a complaint with the state’s veterinary medicine board after a veterinarian made a house call and the family’s dog ended up dying.

The dog’s death happened during a routine operation. The vet’s 16-year-old daughter was performing the anesthesia while the dog was on a kitchen table.

CBS4 Investigator Rick Sallinger learned that most states license vet assistants, but Colorado chose not to.

Colorado looked at licensing veterinary assistants back in 1994 but found there weren’t any incidents that justified it. Now a family has a case they say is worth taking a new look.

His name was Buster, a 3-year-old Yorkshire terrier and an answer to a young girl’s dreams.

“I was so excited to get a new puppy, it was just the happiest day of my life when I first got him,” Bailey Clark said.

The Clarks called on Colorado Mobile Veterinary Services to come to their home to neuter the dog. Dennis Clark says the vet, Dr. Sara Rasmussen, introduced a 16-year-old girl who turned out to be her daughter as her assistant.

The daughter administered the anesthesia to Buster and all seemed to be going well — until monitoring equipment was removed at the end of the operation and the vet examined the dog.

“I knew that something was wrong. She either couldn’t find a heartbeat, he either didn’t have a heartbeat, or it was obviously going in the wrong direction,” Dennis Clark said.

Bailey and her twin sister had been watching and their father suddenly told them to leave. A short time later Buster had stopped breathing.

“That’s when I went up and had the awful chore of telling the girls that he had died,” Dennis Clark said.

Dennis Clark says a necropsy on the dog showed no underlying or pre-existing problem that may have caused the death during the operation.

Since the state veterinary board does not regulate vet assistants the burden is on the vet to oversee the help.

“What we’ve heard so far, what has been alleged, is concerning, and once the board receives a complaint it will look at it,” Maulid Miskell with the Board of Veterinary Medicine said. “It’s unfortunate a pet died while this happened.”

The Clarks wants action.

“I just pet him a lot and it’s just hard to see him go,” Bailey Clark said.

CBS4 contacted Rasmussen who said she is praying for the Clark family. She referred Sallinger to the Colorado Veterinary Medical Association. Its president said anesthesia should be monitored by a knowledgeable and well-trained veterinary technician who can recognize problems and take action under a veterinarian.